A combined algorithm for T-wave alternans qualitative detection and quantitative measurement

• Main Authors: Wan XiangKui, Yan Kanghui, Luo Dehan, Zeng Yanjun
• Format: Article
• Language: English
• Published: BMC 2013-01-01
• Series: Journal of Cardiothoracic Surgery
• Subjects: T-wave alternans; Continuous wavelet transform; Rank-sum test; Quantitive estimation
• Online Access: http://www.cardiothoracicsurgery.org/content/8/1/7

<p>Abstract</p> <p>Background</p> <p>T-wave alternans (TWA) provides a noninvasive and clinically useful marker for the risk of sudden cardiac death (SCD). Current most widely used TWA detection algorithms work in two different domains: time and frequency. The disadvantage of the spectral analytical techniques is that they treat the alternans signal as a stationary wave with a constant amplitude and a phase. They cannot detect non-stationary characteristics of the signal. The temporal domain methods are sensitive to the alignment of the T-waves. In this study, we sought to develop a robust combined algorithm (CA) to assess T-wave alternans, which can qualitatively detect and quantitatively measure TWA in time domain.</p> <p>Methods</p> <p>The T wave sequences were extracted and the total energy of each T wave within the specified time-frequency region was calculated. The rank-sum test was applied to the ranked energy sequences of T waves to detect TWA qualitatively. The ECG containing TWA was quantitatively analyzed with correlation method.</p> <p>Results</p> <p>Simulation test result proved a mean sensitivity of 91.2% in detecting TWA, and for the SNR not less than 30 dB, the accuracy rate of detection achieved 100%. The clinical data experiment showed that the results from this method vs. spectral method had the correlation coefficients of 0.96.</p> <p>Conclusions</p> <p>A novel TWA analysis algorithm utilizing the wavelet transform and correlation technique is presented in this paper. TWAs are not only correctly detected qualitatively in frequency domain by energy value of T waves, but the alternans frequency and amplitude in temporal domain are measured quantitatively.</p>